1. Field of the Invention
The present invention relates to an apparatus for facilitating the finding of the picking end of a yarn wound around a bobbin, wherein the picking end means the end of the yarn with which the whole yarn is drawn out of the bobbin in the subsequent process.
2. Description of the Prior Art
In order to explain the background of the invention, reference will be made to FIGS. 2 to 4:
A fresh yarn from a spinning machine is wound around a bobbin to be in preparation for the subsequent process. To supply the yarn to a cheese or the like, the first thing done by the operator is to find the picking end of the yarn wound around the bobbin. Then the picking end of the yarn is tied by hand to the terminating end of the yarn already wound around the cheese or the like. This is a labor-and time-consuming work.
Recently the speed of winders has been accelarated, and the yarn treating process has become highly automated. The manual work cannot catch up with such speedy and automatic practice. In order to overcome this difficulty, many types of automatic winders have been developed so as to find the picking end of the yarn wound around the bobbin and to tie the same to the bobbin portion of the bobbin automatically. As shown in FIG. 4, the bobbin is hollow or has a bore 2a axially produced, the bore being open in the opposite end faces. The yarn is wound around the bobbin from bottom to top. The starting end of the yarn 1a remains in the bottom portion of the bobbin. The terminating end portion of the yarn 1b is coiled around the wound yarn a few turns as shown in FIG. 2, which is commonly called a doffing coil. At the bottom of the bobbin the doffing coil 1b is overlaid on itself a few turns, thereby holding the starting end of the yarn 1a. The reference numeral 1c indicates this overlaid portion of the yarn. The terminating end and the starting end respectively dangle like animal's tails as shown in FIG. 2. The terminating end of the yarn is subsequently used as the picking end.
When the yarn is unwound from the bobbin, the doffing coil is firstly uncoiled, and the uncoiled portion is straightly turned in the central portion of the wound yarn as shown 1d in FIG. 3. This is done by making the bobbin rotate automatically. During the rotation, the end of the yarn is likely to be lost in the confusingly many yarn lines. In addition, the top and the terminating ends are likely to become tangled with each other. To eliminate the tangles, it becomes necessary to cut the tangled portion, which leads to the waste of yarn.
To avoid the problem of tangling, the common practice is to pass the picking portion of the yarn through the bore of the bobbin from top to bottom as shown at 1f. In FIG. 4 the yarn enters the bobbin at 1e. This practice is now in extensive use because of the advantages that the picking end of the yarn is easily found, thereby facilitating the winding of yarn around a winder, and that it is not necessary to rotate the bobbins.
However, this practice requires a complicated apparatus, which often causes troubles or breakdowns. Due to the frequent stops of operation the working efficiency is immensely reduced.